We all remember our parents telling us that sitting too close to the television would ruin our eyesight, or too much time watching TV would rot our brains. While there’s no good evidence that vision is negatively impacted by proximity to screens, there is some indication that screen time does impact brain health and now we know it might also be making us age more quickly.
It turns out, like the characters of Old, we may be swimming in an ocean which is making us grow older faster than we otherwise would. Instead of a time-bending beach, however, it’s the blue light from our screens doing the damage. A recent study, published in the journal Frontiers in Aging, shows a correlation between extended exposure to blue light and increased rates of aging, at least in flies.
Blue light exposure comes from a variety of sources both natural and artificial. Sunlight includes blue light, along with all other visible wavelengths, and that blue light is part of the signaling process which tells us it’s daytime and helps to kick our bodies into activity. That said, most of us spend a good portion of our lives inside where we’re exposed to blue light from artificial sources like televisions, cell phones, and computers. We’ve known for some time that blue light can negatively impact our ability to sleep, particularly if we’re scrolling the internet at night, by altering our circadian rhythms. That’s part of the reason blue light glasses have become increasingly popular.
While blue light glasses or filters might help to decrease the impact on our sleep cycles — although, the jury is still out on that — there’s little known about how exposure to blue light might impact people holistically over long periods of time. Hoping to shed some light on that, researchers looked to the humble fly. They’re beneficial for longevity studies because of their comparatively short lives and because scientists can experiment on them without the same level of ethical concerns.
Previous studies have shown that flies exposed to 12-hour cycles of blue light exhibited increased rates of aging, but it wasn’t clear precisely why that was. In the new study, scientists used mutated flies which didn’t have eyes, to remove any question about whether or not seeing the light was a factor.
Flies were broken into an experimental and a control group. The experimental group was kept in an environment continually flooded with blue light for 10, 14, or 16 days. The control group flies were kept in perpetual darkness. The experiment showed that flies kept in blue light showed significantly reduced lifespans when compared with the dark-dwelling flies. The decrease in longevity also showed an uptick depending on the duration of exposure.
Post-experimental investigation showed that increased aging was the result of neurodegeneration. It appears that the light penetrates the body and disrupts fuel source production and delivery to the cells. Essentially, the mitochondria — popularly called the powerhouse of the cell — was robbed of its ability to produce power. As a result, cells died, and the flies died with them.
It’s worth noting that these results may not extend to humans in quite the same way, largely because of the vast difference in size. Because of the relatively small size of flies, blue light is able to penetrate throughout their body tissues and get into the brain and other critical body systems. In humans, it’s unlikely that blue light penetrates more than about a millimeter. That means screen time probably isn’t damaging your brain directly through light exposure, but we could be experiencing faster rates of skin degeneration.
Those wrinkles you see could be a consequence of too much time scrolling social media, and not just because you’re constantly screwing up your face at whatever nonsense your uncle is posting.